I've shared this before but I'll share my experience with you. I bought my Husqvarna top of the line machine (at the time) at a quilt show on the mainland and saved almost $2000 off the local price. The local dealer wasn't overjoyed but I'd asked her for her best price before we left for the mainland. No way could she beat the price and the brand new model wasn't available on this island for almost another year (!) anyway.
The point of my story is that Husqvarna has a strict policy that dealers will honor the warranty and service agreements no matter where the machine is bought. Before buying your machine, I'd check with the website of any manufacturer you decide to buy from and make sure that is their policy as well.
That four hour away dealer doesn't sound very reliable to me. Is there another brand of machine you might like just as much with a dealer closer to you?